[PATCH v8 19/24] docs: add support to build manpages from kerneldoc output

Mauro Carvalho Chehab
2025-09-18T11:55:07Z

Generating man files currently requires running a separate
script. The target also doesn't appear at the docs Makefile.

Add support for mandocs at the Makefile, adding the build
logic inside sphinx-build-wrapper, updating documentation
and dropping the ancillary script.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
Documentation/Makefile | 3 +-
Documentation/doc-guide/kernel-doc.rst | 29 ++++-----
Makefile | 2 +-
scripts/split-man.pl | 28 ---------
tools/docs/sphinx-build-wrapper | 81 ++++++++++++++++++++++++--
5 files changed, 95 insertions(+), 48 deletions(-)
delete mode 100755 scripts/split-man.pl

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 05397b9d844d..aa42b2cb7030 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -53,7 +53,7 @@ ifeq ($(HAVE_SPHINX),0)
else # HAVE_SPHINX

# Common documentation targets
-infodocs texinfodocs latexdocs epubdocs xmldocs pdfdocs linkcheckdocs:
+mandocs infodocs texinfodocs latexdocs epubdocs xmldocs pdfdocs linkcheckdocs:
$(Q)@$(srctree)/tools/docs/sphinx-pre-install --version-check
+$(Q)$(PYTHON3) $(BUILD_WRAPPER) $@ \
--sphinxdirs="$(SPHINXDIRS)" --conf="$(SPHINX_CONF)" \
@@ -104,6 +104,7 @@ dochelp:
@echo ' htmldocs - HTML'
@echo ' texinfodocs - Texinfo'
@echo ' infodocs - Info'
+ @echo ' mandocs - Man pages'
@echo ' latexdocs - LaTeX'
@echo ' pdfdocs - PDF'
@echo ' epubdocs - EPUB'
diff --git a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst
index af9697e60165..4370cc8fbcf5 100644
--- a/Documentation/doc-guide/kernel-doc.rst
+++ b/Documentation/doc-guide/kernel-doc.rst
@@ -579,20 +579,23 @@ source.
How to use kernel-doc to generate man pages
-------------------------------------------

-If you just want to use kernel-doc to generate man pages you can do this
-from the kernel git tree::
+To generate man pages for all files that contain kernel-doc markups, run::

- $ scripts/kernel-doc -man \
- $(git grep -l '/\*\*' -- :^Documentation :^tools) \
- | scripts/split-man.pl /tmp/man
+ $ make mandocs

-Some older versions of git do not support some of the variants of syntax for
-path exclusion. One of the following commands may work for those versions::
+Or calling ``script-build-wrapper`` directly::

- $ scripts/kernel-doc -man \
- $(git grep -l '/\*\*' -- . ':!Documentation' ':!tools') \
- | scripts/split-man.pl /tmp/man
+ $ ./tools/docs/sphinx-build-wrapper mandocs

- $ scripts/kernel-doc -man \
- $(git grep -l '/\*\*' -- . ":(exclude)Documentation" ":(exclude)tools") \
- | scripts/split-man.pl /tmp/man
+The output will be at ``/man`` directory inside the output directory
+(by default: ``Documentation/output``).
+
+Optionally, it is possible to generate a partial set of man pages by
+using SPHINXDIRS:
+
+ $ make SPHINXDIRS=driver-api/media mandocs
+
+.. note::
+
+ When SPHINXDIRS={subdir} is used, it will only generate man pages for
+ the files explicitly inside a ``Documentation/{subdir}/.../*.rst`` file.
diff --git a/Makefile b/Makefile
index 6bfe776bf3c5..9bd44afeda26 100644
--- a/Makefile
+++ b/Makefile
@@ -1800,7 +1800,7 @@ $(help-board-dirs): help-%:
# Documentation targets
# ---------------------------------------------------------------------------
DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
- linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
+ linkcheckdocs dochelp refcheckdocs texinfodocs infodocs mandocs
PHONY += $(DOC_TARGETS)
$(DOC_TARGETS):
$(Q)$(MAKE) $(build)=Documentation $@
diff --git a/scripts/split-man.pl b/scripts/split-man.pl
deleted file mode 100755
index 96bd99dc977a..000000000000
--- a/scripts/split-man.pl
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/usr/bin/env perl
-# SPDX-License-Identifier: GPL-2.0
-#
-# Author: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-#
-# Produce manpages from kernel-doc.
-# See Documentation/doc-guide/kernel-doc.rst for instructions
-
-if ($#ARGV < 0) {
- die "where do I put the results?\n";
-}
-
-mkdir $ARGV[0],0777;
-$state = 0;
-while (<STDIN>) {
- if (/^\.TH \"[^\"]*\" 9 \"([^\"]*)\"/) {
- if ($state == 1) { close OUT }
- $state = 1;
- $fn = "$ARGV[0]/$1.9";
- print STDERR "Creating $fn\n";
- open OUT, ">$fn" or die "can't open $fn: $!\n";
- print OUT $_;
- } elsif ($state != 0) {
- print OUT $_;
- }
-}
-
-close OUT;
diff --git a/tools/docs/sphinx-build-wrapper b/tools/docs/sphinx-build-wrapper
index 8d1f77c4a880..7a6eb41837e6 100755
--- a/tools/docs/sphinx-build-wrapper
+++ b/tools/docs/sphinx-build-wrapper
@@ -47,12 +47,14 @@ the newer version.
import argparse
import locale
import os
+import re
import shlex
import shutil
import subprocess
import sys

from concurrent import futures
+from glob import glob

from lib.python_version import PythonVersion
from lib.latex_fonts import LatexFontChecker
@@ -77,6 +79,7 @@ TARGETS = {
"epubdocs": { "builder": "epub", "out_dir": "epub" },
"texinfodocs": { "builder": "texinfo", "out_dir": "texinfo" },
"infodocs": { "builder": "texinfo", "out_dir": "texinfo" },
+ "mandocs": { "builder": "man", "out_dir": "man" },
"latexdocs": { "builder": "latex", "out_dir": "latex" },
"pdfdocs": { "builder": "latex", "out_dir": "latex" },
"xmldocs": { "builder": "xml", "out_dir": "xml" },
@@ -503,6 +506,71 @@ class SphinxBuilder:
except subprocess.CalledProcessError as e:
sys.exit(f"Error generating info docs: {e}")

+ def handle_man(self, kerneldoc, docs_dir, src_dir, output_dir):
+ """
+ Create man pages from kernel-doc output
+ """
+
+ re_kernel_doc = re.compile(r"^\.\.\s+kernel-doc::\s*(\S+)")
+ re_man = re.compile(r'^\.TH "[^"]*" (\d+) "([^"]*)"')
+
+ if docs_dir == src_dir:
+ #
+ # Pick the entire set of kernel-doc markups from the entire tree
+ #
+ kdoc_files = set([self.srctree])
+ else:
+ kdoc_files = set()
+
+ for fname in glob(os.path.join(src_dir, "**"), recursive=True):
+ if os.path.isfile(fname) and fname.endswith(".rst"):
+ with open(fname, "r", encoding="utf-8") as in_fp:
+ data = in_fp.read()
+
+ for line in data.split("\n"):
+ match = re_kernel_doc.match(line)
+ if match:
+ if os.path.isfile(match.group(1)):
+ kdoc_files.add(match.group(1))
+
+ if not kdoc_files:
+ sys.exit(f"Directory {src_dir} doesn't contain kernel-doc tags")
+
+ cmd = [ kerneldoc, "-m" ] + sorted(kdoc_files)
+ try:
+ if self.verbose:
+ print(" ".join(cmd))
+
+ result = subprocess.run(cmd, stdout=subprocess.PIPE, text= True)
+
+ if result.returncode:
+ print(f"Warning: kernel-doc returned {result.returncode} warnings")
+
+ except (OSError, ValueError, subprocess.SubprocessError) as e:
+ sys.exit(f"Failed to create man pages for {src_dir}: {repr(e)}")
+
+ fp = None
+ try:
+ for line in result.stdout.split("\n"):
+ match = re_man.match(line)
+ if not match:
+ if fp:
+ fp.write(line + '\n')
+ continue
+
+ if fp:
+ fp.close()
+
+ fname = f"{output_dir}/{match.group(2)}.{match.group(1)}"
+
+ if self.verbose:
+ print(f"Creating {fname}")
+ fp = open(fname, "w", encoding="utf-8")
+ fp.write(line + '\n')
+ finally:
+ if fp:
+ fp.close()
+
def cleandocs(self, builder): # pylint: disable=W0613
"""Remove documentation output directory"""
shutil.rmtree(self.builddir, ignore_errors=True)
@@ -531,7 +599,7 @@ class SphinxBuilder:
# Other targets require sphinx-build, so check if it exists
#
sphinxbuild = shutil.which(self.sphinxbuild, path=self.env["PATH"])
- if not sphinxbuild:
+ if not sphinxbuild and target != "mandocs":
sys.exit(f"Error: {self.sphinxbuild} not found in PATH.\n")

if builder == "latex":
@@ -619,10 +687,13 @@ class SphinxBuilder:
output_dir,
]

- try:
- self.run_sphinx(sphinxbuild, build_args, env=self.env)
- except (OSError, ValueError, subprocess.SubprocessError) as e:
- sys.exit(f"Build failed: {repr(e)}")
+ if target == "mandocs":
+ self.handle_man(kerneldoc, docs_dir, src_dir, output_dir)
+ else:
+ try:
+ self.run_sphinx(sphinxbuild, build_args, env=self.env)
+ except (OSError, ValueError, subprocess.SubprocessError) as e:
+ sys.exit(f"Build failed: {repr(e)}")

#
# Ensure that each html/epub output will have needed static files
--
2.51.0